1. 1
GENOA and Hyperworks Integration for Advance Composite
Product Design and Analysis
Frank Abdi , Anil Mehta, Harsh Baid, Cody Godines
AlphaSTAR Corporation, Long Beach, CA, USA
and
Robert Yancey, Harold Thomas
ALTAIR Engineering Inc., Irvine, CA
Altair Conference
May 5-7 2015
Detroit Michigan

2. 2
Outline
• AlphaSTAR
• Methodology
– De-homogenized-Multi-Scale Modeling
– Progressive Failure Dynamic Analysis
– Progressive Failure Static Analysis
• Case Studies
– RADIOSS: Numerical Simulations of Composite Tubes
– OPTISTRUCT:
• Lap Shear Damage Mode evolution and Propagation
• Optimization of Storage Tank shape (composite overwrapped Pressure Vessel)
• HMMWV Suspension System
• Summary & Conclusions

3. 3
AlphaSTAR Corporation (ASC)
• Founded in 1989 - Headquartered in Long Beach,
Ca/Rome, Italy
Mission
Provide physics based composites simulation solutions and software
Service industry and government for advanced composite parts/systems
Focus
composites structural design and advanced simulation including: composites, metals,
ceramics, polymer, hybrid
Industry Validated Software
Aerospace: Commercial aircraft Certification by Analysis with Reduced Tests
Automotive: Racing cars, Hydrogen Tank
Infrastructure: Bridge, Wind & Energy
Long Beach, CA
Rome, IT

4. 4
GENOA Composite Multi-Scale Modeling
Computational Tool Predict Test and Consider Uncertainties & Defects
MATERIAL CLASS
• Fiber reinforced polymer composites (Chopped, Continuous)
o Thermoset
o Themo-plastic
o Elastomer
• Metals
o Fracture Toughness
o Fatigue Crack Growth
• Hybrid Composites (Glare)
• Ceramics
• Nano composites
Applicationproduct
• Continuous fiber (MCQ-composite)
• Chopped fiber (MCQ-chopped)
• Ceramics (MCQ-ceramics)
• Nano composites (MCQ-nano)
Manufacture Processes
Applicationproduct
• Filament winding (GENOA GUI)
• Resin Transfer Molding (GENOA GUI)
Durability Damage
Tolerance/Reliability
Applicationproduct
• GENOA running FE (GENOA Suite *)
• GENOA as subroutine (GENOA (V)UMAT)
ABAQUS (V)UMAT Environment Damage Evolution
Integrated MCQ and automatic UMAT generation
as CAE-plugin
Damage Location Ply damage visualization
Failure mode and index
* WWFE I-III Round Robin 1991, 1998, 2013 Journal of Composite Materials, Aug 2013, F Abdi, M Garg, et al.
Product line
Material Characterization &
Qualification (MCQ)

5. 5
De-Homogenized vs. Homogenized Approach
•Chopped Fiber-Elastomer: Galib H. Abumeri, M. Lee, “A Computational Simulation System for Predicting Performance of Chopped Fibers Reinforced Polymer Composites”. ERMR-2006-
Elastomer-Reno Filename: a) 7-06_Abumeri-Paper-ERMR2006.doc; b) 7-06_Presentation-Abumeri-chopped-fiber-ERMR2006.pdf
Schematic View of De-Homogenized vs. Homogenized
• Multi-Scale Modeling of composite constituents
• fiber, matrix, and interface
• Manufacturing Effect of Defects
• fiber waviness, agglomeration, interphase,
• resin rich, void shape/size
• Fiber angle orientation Through-thickness
• Design Parameters Saturation on stiffness/ strength :
•fiber length (limitation using homogenized method)
•fiber shape
Multi-Scale Nano-micro Damage mechanics:
De-homogenization Modeling Approach De-Homogenization Homogenization
* Courtesy of www.mscsoftware.com
* Courtesy of www.mscsoftware.com
Architecture
Homogenized
De-Homogenization Homogenization
* Courtesy of www.mscsoftware.com
* Courtesy of www.mscsoftware.com
Architecture
Homogenized
De-Homogenization Homogenization
* Courtesy of www.mscsoftware.com
* Courtesy of www.mscsoftware.com
Architecture
Homogenized
Homogenization

6. 6
Progressive Failure Dynamic Analysis
• Perform explicit FE analysis at a specified time step
• stress and strain distributions and deformation shape
• Stress and strain calculations in each ply
• Stress and strain calculation in micro-level
• Estimate damage in different length scales
• Ply level failure surface
• Constituent level (fiber-matrix) failure surface – micromechanical approach
• Check convergence criteria
• Number of damaged plies (ply level damage)
• Number of fractured elements (total laminate damage).
• Update the stiffness properties of damaged elements
• Proceed to the next time step/iteration (restart)
Procedure of Explicit Finite Element Framework

7. 7
GENOA Platform
1. UMAT+ GUI Plug In: Integrated with ABAQUS (implicit/explicit), RADIOSS, ANSYS FEA
2. GENOA-MS-PFA: Uses FE solvers as subroutine: (OPTISTRUCT, ABAQUS, LSDYNA, NASTRAN)
3. Damage/Fracture Evolution: GENOA GUI
GENOA
Abaqus
Radioss
Ansys
GENOA
Optistruct
* ABAQUS, Optistruct, LSDYNA,
ANSYS, NASTRAN and MHOST
GENOA is an augmentation to FEA software with 2 Options + pre/ post
UMAT+GENOA GUI
GENOA with ALL FEA*
Radios UMAT Environment
Damage Evolution
Damage Index

8. 8
Technical Approach: Damage & Fracture Evolution
Delamination Regions (Overlap Damage/Fracture)
Fracture Mechanics DelaminationDamage Mechanics Delamination Type
ILT
ILS
RROT
Simulation Process
• STEP 1: Simulate the problem with PFA (Stage1-5)
• Estimate damage accumulation in FE model
• Predict damage and failure initiation and damage propagation
• Predict crack path
• STEP 2: Simulate with VCCT/DCZM (Stage 3-5)
• Prepare a coarser FE model again with pre-defined crack path
(predicted via PFA simulation or test)
• Simulate and predict complete damage and failure process
(damage initiation and propagation, crack initiation and propagation
and final failure) of the component
• DCZM combined with PFA to account for damage accumulation for
improved predictions
• STEP 3: combined PFA+VCCT/DCZM (Stage 1-5)
8

9. 9
PFA takes full-scale FEM and breaks material properties down to microscopic level.
Material properties are updated, reflecting any changes resulting from damage or crack
In-Depth Evaluation of Multi-scale Process
Vehicle Component Laminate
3D Fiber, Weave,
Stitch
Lamina
2D Woven
Decomposition
Traditional FEM Stops Here
GENOA goes down to micro
scale
Unit cell
At node or
element
depending on
solver
Sliced Unit Cell
Micro Scale
FEM results decomposed to
micro scale
Reduced properties
propagate up to vehicle scale

10. 10
*Options: Tsai-Wu, Tsai-Hill, Hashin, User defined criteria, Puck, SIFT,
**Honeycomb: Wrinkling, Crimpling, Dimpling, Intra-cell buckling, Core crushing.
*** Environmental: Recession, Oxidation (Global, Discrete), aging, creep
Ref: C. Chamis, F. Abdi, M. Garg, L. Minnetyan, H. Baid, D. Huang, J.Housner, F. Talagani,” Micromechanics-based progressive failure analysis prediction for WWFE-III composite coupon test
cases”. Journal of Composite Materials Part A 47(20–21) 2695–2712, 2013
Damage, and Fracture Mechanics based
Unit Cell
damage
criteria
Delam
criteria
MATRIX
1. Micro crack Density (TT) ,LT
2. Matrix: Transverse tension
3. Matrix: Transverse compression
4. Matrix: In-plane shear (+)
5. Matrix: In-plane shear (-)
6. Matrix: Normal compression
FIBER
7. Fiber: Longitudinal tension
8. Fiber: Longitudinal compression
9. Fiber Probabilistic
10.Fiber micro buckling
11.Fiber crushing
12.Delamination
DELAMINATION
15. Normal tension
16. Transverse out-of-plane shear (+)
17. Transverse out-of-plane-shear (-)
18. Longitudinal out-of-plane shear (+)
19. Longitudinal out-of-plane shear (-)
20. Relative rotation criteria
21. Edge Effect
13.Strain limit
FRACTURE
22. LEFM :VCCT (2d/3d)
23. Cohesive: DCZM (2d/3d)
24. Honeycomb**
25. Environmental***
14. INTERACTION*
• MDE (stress) or SIFT (strain)
Multi-Scale Multi Failure Criteria

11. 11
• Good agreement between the
deformation mode from
experiment and simulation
• Similar deformation mode
approves the energy absorption
mechanism observed in the
experiment.
Crush Tubes Progressive Damage Analysis
Deformations from Experiment
Deformations from Simulation
Progressive damage analysis used to Simulate crush tubes

12. 12
Energy Absorption Characteristics
• Crush load versus crush distance as a measure of energy absorption
• Tape composite systems considered
• Serrations arise as a result of the stick-slip nature of crushing mechanism
• required stress to initiate microcracks and damage are higher than those for propagation
• Higher second peak observed
Crush load versus crush distance of tape laminate with the
layup of [45/0/-45/0/-45/0/45]
Damage Index Table
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
CrushForce(Normalized)
Crush Displacement (Normalized)
TEST 1
TEST 2
TEST 3
GENOA PFA + MDNASTRAN
GENOA+RADIOSS: Good Agreement Between Test and Simulation

13. 13
Damage Evolution Distribution During Crushing Process
Fiber Longitudinal compressive failure (11C)
Crush
Distance
Δ=15 mm
(1.88%*)
Δ=40 mm
(5.00%*)
Δ=80 mm
(10.00%*)
Δ=350 mm
(43.75%*)
Defromati
onState
Ply 1
Ply 2
Ply 3
Ply 4
Ply 5
Ply 6
Ply 7

14. 14
Chopped Fiber Composite: Crush Modeling Process
Determine Ply Angle Through Thickness – De-Homogenization Approach
Shell Model – Low Fidelity
Orientation Data Moldex3D Model
2 mm Laminate PART
Orientation Tensor Mapping
• Material Characterization
• Mapping from Un- structured mesh to structured mesh using orientation tensor
• De-Homoginization Process: Determine Chopped fiber orientation through-the-thickness
• Multi-Scale damage assessment by Progressive Failure Analysis:
Mapping (un-structured to Structured/solid)

15. 15
Validation: Chopped Fiber Composite Characterization
Simulation Vs. Coupon Tests (PBT-GF20)
Flow, Cross Flow, Shear (Stress-Strain)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Orientation
NormalizedThickness[z/H]
Test-A11 Test-A22 Test-A33
MCQ-A11 MCQ-A22 MCQ-A33
Orientation Distribution Vs. Test
3 point Bending Coupon Analysis
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 2 4 6 8 10NormalizedLoad
Displacement[mm]
Flow-Test Cross-Flow-Test
Flow-MCQ-GENOA Cross-Flow-MCQ-GENOA
Flow, Cross Flow (L-D Curves)
Through-thickness
damage
Ref: H.K. Baid, F. Abdi, M. C. Lee, Uday Vaidya, “Chopped Fiber Composite Progressive Failure Model under Service Loadin”,SAMPE 2015
0.00 0.01 0.02 0.03 0.04
Strain [mm/mm]
Stress[MPa]
Test-Flow Test-45-Deg Test-Cross-Flow
MCQ-Flow MCQ-45-Deg MCQ-Cross-Flow

16. 16
Chopped Fiber Crush Tube AnalysisAcceleration(m/s2)
Time (s)
Test
De-homogenized
Load Displacement Curves
10 (ms) 20 (ms)
30 (ms) 40 (ms)
Deformation Vs. Time
Acceleration Vs. Time
Explicit chopped fiber crush tube simulation
NormalizedLoad
Displacement
TEST
De-Homogenized
Simulation results matches well with test

17. 17
Effect of Weak Interphase & Agglomeration
Effect of Defects
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
Baseline Interphase Agglomeration
Young'sModulus[GPa]
0
50
100
150
200
250
300
350
Baseline Interphase Agglomeration
Strength[MPa]
Tensile Strength
Compressive Strength
Shear Strength
Nano-comp: Mohit Garg, F. Abdi, J. Housner, “PREDICTION OF EFFECT OF WAVINESS, INTERFACIAL BONDING AND AGGLOMERATION OF CARBON NANOTUBES ON THEIR
POLYMER COMPOSITES ”. SAMPE- Conference, Longbeach, Ca-may2013.
Predicted modulus, tensile, compressive and shear strengths for the 3D randomly oriented MWCNTs in
epoxy; baseline; baseline with interphase of 1 nm thickness and baseline with agglomeration (no
interphase); amplitude (a) = 0.0 to 700.0 nm
Modulus Effect Strength Effect

18. 18
Experiments – Modified Thick Lap Shear Test
18
• ASTM standard D5656 test
• The film adhesive bondline
thickness are 0.01” – 0.03”
Modified ASTM D5656 - Thick Lap shear Test
* A modified extensometer is implemented
to improve strain measurement
A modified biaxial extensometer allows accurate measurement
Test Shows Adhesive Failure
Test and analysis average shear stress-
strain curve ASTM D5656
Ref: Yibin Xue, Frank Abdi, Suresh Keshavanarayana, and Waruna Senevirantne, “Physics-based modeling and progressive failure and probabilistic sensitivity analysis for adhesively
bonded structural components, ”, 10th International Conference On Durability Of Composite Systems, September 16-18, Brussels Belgium

19. 19
Multi-Scale Material Modeling
19
Assumed Reverse Engineered Effective Matrix Equivalent SS Curve from
MCQ Composites Material Library
0
20
40
60
80
100
120
140
0.00 0.10 0.20 0.30
Stress[MPa]
Strain [mm/mm]
Effective Equivalent Matrix SS Curve
Effective Matrix Equivalent SS Curve Bond Properties (PU-1340)
0
10
20
30
40
50
60
70
0.00 0.01 0.02 0.03 0.04
Stress[MPa]
Strain [mm/mm]
PU-1340 SS Curve (Engineering)
Test
Bond Test (Mechanical Properties)
Bond Test (Strain)
PU-1340
Strain Limit Value
Eps11T 3.147E-02
Eps22T 3.147E-02
Eps33T 3.147E-02

20. 20
Results: Load Displacement Curve FE Model
Damage Progression Events & Failure Modes
B
C
E
A
D
F
Normal tension [Eps33T]
All DamageAll Damage
Transverse Out-plane Shear strain [Eps23S]
Longitudinal Compression Strength [S11C]
Normal tension Strain[Eps33T]
Final Damage
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Load(N)
Displacement(mm)
Test
MS-PFA
A
B
C D
E
F
Ref: S. DorMohammadi, F. Abdi, C.Godines, R. Yancey, H. Thomas, " Zig-Zag Crack Growth Behavior of Adhesively Bonded Lap shear specimen",
SAMPE/CAMX Oct, 2014,. Orlando Floida

21. 21
Hybrid Suspension Damage
Fracture of Upper Control Arm
At Ultimate Load
Damage/Fracture Modes
Steel
Steel
Damage Initiates in Steel in
Upper Control Arm Fractured Suspension Unit
Damage Evolution Under Static Loading
Reference: G. Abumeri, B. K. Knouff, D. Lamb, D. Hudak, and R. Graybill, “BENEFITS OF HIGH PERFORMANCE COMPUTING IN THE DESIGN OF LIGHTWEIGHT ARMY VEHICLE
COMPONENTS”, Presented ArmyScienceCOnference-Nov2010, Orlando, FL
Improved L-D curve

22. 22
Failure Locations
Spring Support
Upper Control Arm
Lower Control Arm
Spindle is Damaged because
of modeling constraints
GENOA Predicted Damage Under Fatigue Spectrum Cycling Loading
Ref: G. Abumeri, M. Garg, D. Lamb, “Technical Approach for Coupled Reliability-Durability Assessment of Army Vehicle Sub-Assemblies ”. SAE World Congress, 2008, 08M-126, Detroit Mi, April
2008.
HMMWV: Durability of double A-arm suspension

23. 23
3D printing process introduces significant thermal loading in structure
3D-Printing BAAM
•Thermoplastic resin (ABS) reinforced with
chopped carbon fiber is placed while hot and
not fully solidified. Layer by layer (beads) the
3D structure is produced.
Cross section of
two beads
Robot printer head
Delamination
Thermo-graphical image
of the printing process
Printing process
•Temperature difference and cohesion
between the individual beads,
• results in asymmetric shrinkage,
• bending moments introduced in structure
V. Kunc, B. Compton, S. Simunovic, C. Duty, L. Love, B. Post, C. Blue1, F. Talagani, R. Dutton, C. Godines, S. DorMohammadi, H. Baid, F. Abdi , “Modeling of Large Scale Reinforced
Polymer Additive Manufacturing”, Anetc Conference Orlando Florida. March 23- 2015.

24. 24
Damage and fracture evolution analyzed in ~12 hrs
3D-Print –Strati Car
Delamination during simulation
Fracture evolution pattern
Production process simulation
Damage location and % of contributing
failure mechanisms

25. 25
Approach: model generator; characterize chopped fiber; progressive damage/fracture analysis
3D-Print: Solution approach
Multiple solution strategies have been considered
Tensor orientation

26. 26
Delamination Initiation
(P= 22.06 MPa)
Burst Initiation
(P = 34.75 MPa)
Delamination Progression
(P= 30.9 MPa)
Durability: Delamination Initiation / Progression and Fracture Simulation
Test
Test
Reliability: Predict scatter in failure load, ranking of random variables
Test Burst pressure: 33.72 to 36.56 MPa
(Low-Fidelity Durability and Reliability)
20.7 27.6 34.5 41.4 48.3 55.2
[MPa]
Tank Storage Analysis/Validation
G. Abumeri, F. Abdi, M. Baker, M. Triplet and, J. Griffin “Reliability Based Design of Composite Over-Wrapped Tanks”. SAE World Congress, 2007, 07M-312, Detroit Mi, April 2007

27. 27
High Fidelity Validation
US Army Optimized COPV Tank Failure process
Damage Initiation
(3 Mpa)
50% pressure
(15.5 MPa)
Fiber Failure (Final Burst)
(31 MPa)
75% pressure
(21.7 MPa)

28. 28
High Fidelity Validations: Optimized COPV
Process of Shape Optimization and design dome parameter from
OPTISTRUCT

29. 29
Summary & Conclusions
• MCQ performs material characterization and qualification including PFA.
• Virtual testing is made possible by conducting PFA and combining those results
to predict structure/component safety based on physics and micro/macro
mechanics of materials, manufacturing processes, available data, and service
environments.
• The approach takes progressive damage and fracture processes into account and
accurately assesses reliability and durability by predicting failure initiation and
progression based on constituent material properties.
• Such approaches are becoming more widespread and economically
advantageous in some applications
• Composite Multi-scale Modeling De-Homogenized Approach validated with test
for various applications: (1) Crush tubes; (2) Lap-shear; (3) 3D printing; (4) Storage tank
• GENOA-PFA enabled the application of multi-scale progressive failure Dynamic
criteria with ALTAIR products (RADIOSS and OPTISTRUCT).